<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    .lgch-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 230px;
    height: 90px;
    line-height: 90px;
    text-align: center;
    color: #fff;
    font-size: 25px;
    text-transform: uppercase;
    cursor: pointer;
    background: linear-gradient(90deg, #03a9f4, #f441a5, #ffeb3b, #03a9f4);
    background-size: 400%;
    border-radius: 60px;
  }

  .lgch-btn:hover {
    animation: animate 8s linear infinite;
  }

  @keyframes animate {
    0% {
      background-position: 0%;
    }

    100% {
      background-position: 400%;
    }
  }

  .lgch-btn::before {
    content: '';
    position: absolute;
    top: -5px;
    left: -5px;
    right: -5px;
    bottom: -5px;
    z-index: -1;
    background: linear-gradient(90deg, #03a9f4, #f441a5, #ffeb3b, #03a9f4);
    background-size: 400%;
    border-radius: 40px;
    opacity: 0;
    transition: 0.5s;
  }

  .lgch-btn:hover::before {
    filter: blur(20px);
    opacity: 1;
    animation: animate 8s linear infinite;
  }

    </style>
</head>
<body>
    <a href="#" class="lgch-btn">button</a>
  </body>
</html>
